title: Comparison between rDNA magnification and bb lethal mutation frequencies in Drosophila melanogaster.
abstract: Unequal mitotic sister strand crossing over has been evoked to explain the occurrence of phenotypically bb+ males in the progeny of phenotypically bobbed males during magnification. If this is the case, complementary bbl loci should be obtained together with the bb+. To test this hypothesis we compared the frequency of bb lethal mutations in the sperms of bb males with the percentages of phenotypically bb+ males obtained during magnification of these bb males. We then compared these values with those occurring in phenotypically bb+ control males. We found that, while the number of bb+ males obtained during magnification, though variable, is high, the bb lethal mutation occurs at a very low frequency in all the genetic conditions, whatever the phenotype of the parental male.
mesh_terms: D000818:Animals; D004261:DNA Replication; D004331:Drosophila melanogaster / Q000235:genetics*; D005787:Gene Frequency; D005804:Genes, Lethal; D005838:Genotype; D008297:Male; D009154:Mutation; D010641:Phenotype; D012335:RNA, Ribosomal / Q000235:genetics*; D013094:Spermatozoa / Q000378:metabolism
chemical_list: D012335:RNA, Ribosomal